The present invention relates to a method for adjusting the volume in a mobile telephone comprising a transceiver unit and a physically separated operating device. The invention also relates to a circuit arrangement realizing the method.
In mobile telephones, the speaker amplifier is located in the transceiver unit in order to conserve space and power. It is known to use plus and minus buttons to adjust the volume of the speakers. In practice, however, it was found that a user experiences difficulties in using these plus and minus buttons directly in the transceiver unit, for example as a potentiometer, but for the user this again results in cumbersome adjustment.
It is possible to reduce the number of conductors between the operating device and the transceiver when the speaker amplifier is placed in the operating device, and at the same time audio signal interferences may be reduced. However, this complicates the use of an external speaker, and creates inconvenient currents between the operating device and the transceiver.